Is socioeconomic status associated with dietary sodium intake in Australian children? A cross-sectional study.

Grimes CA, Campbell KJ, Riddell LJ, Nowson CA - BMJ Open (2013)

Bottom Line:
SES was defined by the level of education attained by the primary carer.In addition, parental income was used as a secondary indicator of SES.Australian children from a low SES background have on average a 9% greater intake of sodium from food sources compared with those from a high SES background.

Objective: To assess the association between socioeconomic status (SES) and dietary sodium intake, and to identify if the major dietary sources of sodium differ by socioeconomic group in a nationally representative sample of Australian children.

Design: Cross-sectional survey.

Setting: 2007 Australian National Children's Nutrition and Physical Activity Survey.

Participants: A total of 4487 children aged 2-16 years completed all components of the survey.

Primary and secondary outcome measures: Sodium intake was determined via one 24 h dietary recall. The population proportion formula was used to identify the major sources of dietary salt. SES was defined by the level of education attained by the primary carer. In addition, parental income was used as a secondary indicator of SES.

Conclusions: Australian children from a low SES background have on average a 9% greater intake of sodium from food sources compared with those from a high SES background. Understanding the socioeconomic patterning of salt intake during childhood should be considered in interventions to reduce cardiovascular disease.

BMJOPEN2012002106F1: Mean sodium intake (mg/day) by socioeconomic group (n=4487)*Significantly different from high socioeconomic status (SES) (p < 0.001). **Significantly different from high SES (p< 0.05). †SES as defined by the highest level of education attained by the primary carer.

Mentions:
Basic characteristics of the 4487 participants are listed in table 1. As defined by parental education status, the proportion of children from low, medium and high SES backgrounds was relatively evenly distributed. Over two-thirds of children fell within the two highest income bands. There was a significant positive correlation between sodium intake and energy intake (r=0.69, p<0.001) and sodium intake and BMI (r=0.22, p<0.001). Average daily sodium intake differed by SES (figure 1, p<0.01). Regression analysis indicated that low SES was associated with a 195 mg/day (salt 0.5 g/day) greater intake of sodium. The association between SES and sodium intake remained after adjustment for age, gender, energy intake and BMI (table 2). When stratified by the age group, the association between sodium intake and SES remained significant between the ages of 4–13 years (table 2); however, there was no association between sodium intake and SES in 2-year-olds to 3-year-olds or in 14-year-olds to 16-year-olds (data not shown). There was no association between sodium intake and parental income (data not shown); however, only 28% of children fell within the two lowest income bands (table 1). Table 3 lists those submajor food groups which contributed >1% to the groups’ total daily sodium intake. Combined, these 23 food groups accounted for 84.5% of the total daily sodium intake. Regular breads and bread rolls contributed the most sodium (13.4%). Moderate sources of sodium, contributing more than 4% of the total sodium intake, included mixed dishes where cereal is the major ingredient (eg, pizza, hamburger, sandwich, savoury rice and noodle-based dishes), processed meat, gravies and savoury sauces, pastries, cheese and breakfast cereals and bars. Compared with children of high SES, children of low SES had a significantly greater intake of sodium from processed meat, gravies and savoury sauce, pastries, breakfast cereals and bars, potatoes and potato snacks (eg, potato crisps). The percentage difference in sodium intake in each of these categories was 46%, 31%, 24%, 16%, 39% and 46%, respectively (table 3). Conversely, children of high SES background had a significantly greater intake of sodium from the food group containing cakes, buns, muffins, scones, cake-type desserts, and from the food group described as batter-based products (eg, pancakes and picklets). The percentage difference in sodium intake in each of these categories was 16% and 32%, respectively (table 3).

BMJOPEN2012002106F1: Mean sodium intake (mg/day) by socioeconomic group (n=4487)*Significantly different from high socioeconomic status (SES) (p < 0.001). **Significantly different from high SES (p< 0.05). †SES as defined by the highest level of education attained by the primary carer.

Mentions:
Basic characteristics of the 4487 participants are listed in table 1. As defined by parental education status, the proportion of children from low, medium and high SES backgrounds was relatively evenly distributed. Over two-thirds of children fell within the two highest income bands. There was a significant positive correlation between sodium intake and energy intake (r=0.69, p<0.001) and sodium intake and BMI (r=0.22, p<0.001). Average daily sodium intake differed by SES (figure 1, p<0.01). Regression analysis indicated that low SES was associated with a 195 mg/day (salt 0.5 g/day) greater intake of sodium. The association between SES and sodium intake remained after adjustment for age, gender, energy intake and BMI (table 2). When stratified by the age group, the association between sodium intake and SES remained significant between the ages of 4–13 years (table 2); however, there was no association between sodium intake and SES in 2-year-olds to 3-year-olds or in 14-year-olds to 16-year-olds (data not shown). There was no association between sodium intake and parental income (data not shown); however, only 28% of children fell within the two lowest income bands (table 1). Table 3 lists those submajor food groups which contributed >1% to the groups’ total daily sodium intake. Combined, these 23 food groups accounted for 84.5% of the total daily sodium intake. Regular breads and bread rolls contributed the most sodium (13.4%). Moderate sources of sodium, contributing more than 4% of the total sodium intake, included mixed dishes where cereal is the major ingredient (eg, pizza, hamburger, sandwich, savoury rice and noodle-based dishes), processed meat, gravies and savoury sauces, pastries, cheese and breakfast cereals and bars. Compared with children of high SES, children of low SES had a significantly greater intake of sodium from processed meat, gravies and savoury sauce, pastries, breakfast cereals and bars, potatoes and potato snacks (eg, potato crisps). The percentage difference in sodium intake in each of these categories was 46%, 31%, 24%, 16%, 39% and 46%, respectively (table 3). Conversely, children of high SES background had a significantly greater intake of sodium from the food group containing cakes, buns, muffins, scones, cake-type desserts, and from the food group described as batter-based products (eg, pancakes and picklets). The percentage difference in sodium intake in each of these categories was 16% and 32%, respectively (table 3).

Bottom Line:
SES was defined by the level of education attained by the primary carer.In addition, parental income was used as a secondary indicator of SES.Australian children from a low SES background have on average a 9% greater intake of sodium from food sources compared with those from a high SES background.

Objective: To assess the association between socioeconomic status (SES) and dietary sodium intake, and to identify if the major dietary sources of sodium differ by socioeconomic group in a nationally representative sample of Australian children.

Design: Cross-sectional survey.

Setting: 2007 Australian National Children's Nutrition and Physical Activity Survey.

Participants: A total of 4487 children aged 2-16 years completed all components of the survey.

Primary and secondary outcome measures: Sodium intake was determined via one 24 h dietary recall. The population proportion formula was used to identify the major sources of dietary salt. SES was defined by the level of education attained by the primary carer. In addition, parental income was used as a secondary indicator of SES.

Conclusions: Australian children from a low SES background have on average a 9% greater intake of sodium from food sources compared with those from a high SES background. Understanding the socioeconomic patterning of salt intake during childhood should be considered in interventions to reduce cardiovascular disease.